libata: handle pci_enable_device() failure while resuming

Handle pci_enable_device() failure while resuming.  This patch kills
the "ignoring return value of 'pci_enable_device'" warning message and
propagates __must_check through ata_pci_device_do_resume().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/sata_sil.c b/drivers/ata/sata_sil.c
index d27ab31..1f3fdcf 100644
--- a/drivers/ata/sata_sil.c
+++ b/drivers/ata/sata_sil.c
@@ -710,8 +710,12 @@
 static int sil_pci_device_resume(struct pci_dev *pdev)
 {
 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	int rc;
 
-	ata_pci_device_do_resume(pdev);
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
+
 	sil_init_controller(pdev, host->n_ports, host->ports[0]->flags,
 			    host->mmio_base);
 	ata_host_resume(host);